In “Personal Shopper”, a film of Olivier Assayas (“Paris, je t’aime” (2006)), Kristen Stewart plays a young woman Maureen who mourns the loss of her twin brother Lewis. Maureen visits the house where Lewis lived with his girlfriend, and believes that his ghost will try to communicate with her. In her daily job, Maureen is a personal shopper to a rich and famous star in Paris, a job she dislikes and only too keen to break the “rules” of her employment now and then. Soon her personal identity issues mix with her paranormal beliefs, producing restlessness and paranoia. Although admirable in its fresh approach, the film is also unfocused and dull. It tries at least three different points of focus: a ghost story; a murder mystery; and a high-society critique, all of which are underdeveloped and none of which work to a satisfactory conclusion.